[Cutaneous signs of occult cranial and spinal dysraphism].

Dysraphism refers to neural tube closure abnormalities and midline closure abnormalities of the skin, paravertebral muscles, vertebrae and meninges. Cranial dysraphism (CD) and occult spinal dysraphism (OSD) may be discovered via evocative skin signs present at birth or appearing later in childhood or even in adulthood. This review describes the various types of skin signs associated with CD and OSD. All congenital midline skin lesions, particularly on the frontonasal area, the vertex or the occipitocervical and low back regions, should prompt suspicion of underlying dysraphism. The main evocative midline skin abnormalities are: (i) for underlying DCEO: a nodule, swelling, skin openings and hair collar sign or hair tuft; (ii) for underlying DSO, localized hypertrichosis, an atypical or complex lower back dimple, a dermoid fistula, infantile haemangioma, caudal appendage and lipoma. In the event of suspected DCEO or DSO, spinal or medullary MRI constitutes the reference examination.